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Autumn Budget 2026: Stamp Duty & Mansion Tax — What's Changing on 28 October

Developing storyThis page covers proposals and reported plans that are not yet confirmed government policy. We’ll update it — and the two related pieces below — within 24 hours of the Budget speech on 28 October 2026 with exactly what was announced, replacing every "reported" or "proposed" label below with "confirmed" or "did not happen."

The Autumn Budget lands on 28 October 2026. Stamp duty itself looks safe — but a genuine, already-announced tax on high-value homes is moving toward 2028, and there's live reporting on it changing shape before then. Here's exactly what's confirmed, what's ruled out, and what we're watching for on the day.

Published

Illustration of a government building flanked by a document marked 28 and a pound coin, representing the 28 October Budget.

Who's delivering this Budget

The Autumn Budget 2026 is confirmed for 28 October 2026. It's the first full Budget delivered under Prime Minister Andy Burnham, who succeeded Keir Starmer on 19 July 2026, with John Healey appointed Chancellor of the Exchequer shortly after. That change of leadership matters here mainly because it's fed a wave of speculation about property tax reform — some of it accurate reporting on live proposals, some of it, according to Downing Street, "pure speculation."

Stamp duty itself: ruled out

Start with the clearest fact available before the Budget: the government has explicitly ruled out changing stamp duty at this Budget. Asked directly about it, the Prime Minister was reported as saying "that won't be happening," and also rejected the idea of scrapping stamp duty and council tax entirely in favour of a single annual property tax — calling that kind of proposal unfounded speculation.

That's a meaningful thing to confirm, because stamp duty reform has genuinely been under discussion this year — we cover every proposal actually in circulation, and their real status, in a separate piece linked below. For this specific Budget, though, the reported government position is: no change to stamp duty rates, thresholds, or reliefs.

What is actually moving: the "mansion tax"

Separately from stamp duty, there's a real, already-announced policy in motion: the High Value Council Tax Surcharge, nicknamed the "mansion tax." This was announced in the 2025 Budget, not this one, and it's the clearest example of a genuine, confirmed reform actually working its way toward implementation.

As announced: homes worth £2 million or more in England would carry an annual surcharge, billed alongside the existing council tax bill and collected by local authorities on the government's behalf. It's tiered — from £2,500 a year for homes between £2m and £2.5m, rising to £7,500 a year for homes over £5m — and only the property's owner is liable, not whoever lives there. A public consultation was planned for early 2026, with implementation targeted for April 2028 and annual increases indexed to inflation from 2029/30.

The open question: could the threshold drop to £1.5m?

This is where this Budget genuinely could move the story on. Reporting since the summer — the Mail on Sunday in July 2026, and The Times in September 2026 — suggests the Treasury is actively considering lowering that £2m threshold to £1.5 million, which would roughly double the number of homes caught: from an estimated 123,000 up to around 245,000. Around 85% of the newly-caught homes would be in London and the South East, with Surrey the single largest affected local authority outside London itself.

None of this is confirmed. Both outlets describe it as "under active consideration" or something Burnham "might" do — language that reflects genuine internal deliberation, not an announced decision. Treat it exactly as that until 28 October says otherwise.

Already announced (2025 Budget)

  • £2m+ threshold, tiered £2,500–£7,500 a year
  • Billed via council tax, owner liable
  • Consultation planned early 2026
  • Implementation targeted April 2028

Reported, not yet confirmed

  • Threshold possibly lowered to £1.5m
  • ~245,000 homes affected, up from ~123,000
  • New top band modelled at £10,000/yr for £5m+
  • No official confirmation from HM Treasury

What we'll check on 28 October

When the Budget is actually delivered, we'll check the official HM Treasury documents — not headlines — for:

Official source

GOV.UK and HM Treasury publish the actual Budget documents on the day. That's the only source we treat as confirmation — not pre-Budget reporting, however well-sourced.

Frequently asked questions

Is stamp duty changing on 28 October 2026?

As of this reporting, no — the government has explicitly ruled out changes to stamp duty at this Budget. That's a reported position, not a legal guarantee, so we'll confirm it directly against the actual Budget documents on the day and update this page immediately if anything changes.

What is the “mansion tax” exactly?

It's the nickname for the High Value Council Tax Surcharge, an annual charge on homes worth £2 million or more, announced in the 2025 Budget. It's billed alongside council tax rather than being a new separate tax, and only the property owner is liable for it.

When would the mansion tax actually start?

Under the plan as announced, implementation is targeted for April 2028, following a public consultation planned for early 2026. Those dates haven't changed as far as official confirmation goes, but this Budget is a moment where they could be revisited.

Could the £2m threshold really drop to £1.5m?

It's being actively reported — the Mail on Sunday in July 2026 and The Times in September 2026 both describe it as under consideration — but neither the Treasury nor Downing Street has confirmed it. Until the Budget, this should be read as a live possibility, not a decision.

Where can I check what was actually announced, rather than rely on this page?

HM Treasury publishes the full Budget documents on GOV.UK on the day itself. We'll read those directly and update this page, and the two linked below, within 24 hours — but the primary source is always GOV.UK first.

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About the author

Written by Parm Uppal, who has spent over 25 years helping people get back on track with their finances. This piece tracks reported plans versus confirmed policy — the line between the two is the whole point.

This page is for general information and doesn't constitute financial or legal advice. Everything above marked "reported" or "proposed" is not confirmed government policy — always check GOV.UK and HM Treasury's official Budget documents directly before making a financial decision.